The invention concerns a boarding device, designed to enable passengers to embark and disembark from an aircraft in the shortest possible time.
Such a device is principally intended for very large capacity aircraft, in which the embarking and disembarking times are particularly long.
The invention also covers a flying wing equipped with such a boarding device.
In aircraft dedicated to the commercial transportation of passengers, access for boarding is achieved via side doors which open directly into the aircraft fuselage.
On existing aircraft, there are different types of doors. More precisely, they are classified according to their dimensions and the number of passengers which they are able to evacuate simultaneously during an emergency. Thus on large capacity aircraft, the dimensions of the doors and the characteristics of their associated escape slides are able to evacuate passengers two at a time.
If one considers existing aircraft doors merely from the point of view of embarking and disembarking of passengers, their dimensions are inadequate. Every day, passengers are complaining that these operations are always long and fastidious at stop-overs. Moreover these problems are becoming worse as the number of passengers carried increases.
The number of passengers carried in the aircraft currently being designed by the manufacturers, is significantly greater than in existing aircraft. Thus xe2x80x9cflying wingxe2x80x9d type aircraft will be capable of carrying around 900 passengers, i.e. nearly double the numbers carried in present-day large capacity airliners.
The use of conventional access doors for embarking and disembarking such a quantity of passengers would lead to transfer times which would be difficult to accept.
The problem is even more serious if one considers the emergency evacuation of passengers. On airliners intended for carrying passengers, the latter must be able to be evacuated, on the ground, in critical situations, such as for example a wheels-up landing. The evacuation of passengers must then be achieved as quickly as possible, whilst at the same time avoiding injuries such as burns, sprains, etc.
On existing aircraft, evacuation of passengers on the ground, takes place laterally, from each side of the aircraft, via the doors used for embarking and disembarking passengers, and via emergency exits opening onto the wings.
Emergency evacuation slides are associated with these various emergency exits, in order to permit rapid evacuation of the passengers following a crash. These slides usually consist of inflatable structures, which are stored folded in a special location inside the aircraft.
This conventional solution is illustrated in particular in document U.S. Pat. No. 4,512,539, which describes a device for automatically deploying an inflatable slide from a lateral access door, when the door is opened in an emergency situation.
The certification authorities"" regulations stipulate that total evacuation of an aircraft must be achieved within 90 seconds. This time interval begins when the evacuation signal (illuminated signs, audio signal etc.) is given and ends when the entire crew and passengers reach the ground. This therefore includes opening of the doors, inflation of the escape slides, evacuation of the passengers, checking by the crew that all passengers have in fact left the aircraft, and evacuation of the crew. These various stages are made all the more difficult to implement within the allocated time, since one must take into account the inevitable hesitation of the passengers before using the escape slides, as well as the generally angular route adopted by passengers to reach the emergency exits.
On existing aircraft, the use of large size doors and suitable slides enables the evacuation of average sized passengers two abreast. This enables the aircraft to be totally evacuated within the 90-second time allotted by the certification authorities.
However, the use of these type of doors on aircraft capable of carrying up to double the number of passengers than on existing aircraft, would not enable all the passengers to be evacuated within the allotted time without drastically increasing the number of exits.
Additionally, in the particular case of an aircraft with no fuselage, such as a flying wing, the solutions habitually used are not directly applicable. Thus for example, one cannot transpose to such an aircraft, the emergency exits located above the wing of a conventional aircraft, since there is no fuselage-wing joint on an aircraft which has no fuselage.
On the xe2x80x9cflying wingxe2x80x9d type of aircraft currently being studied, it is intended to locate a large number of access doors at the extreme front of the aircraft, for embarkation, disembarkation and emergency evacuation of the passengers. However, this solution is not altogether satisfactory. In the event of a landing in an unsafe area (forest, etc.), the resulting structural damage would be likely to render the emergency exits unusable.
Another solution consists in using a closed rescue capsule to bring the passengers of an aircraft in distress, safely back to earth or the sea.
A solution of this type is described in document FR-A-1 603 439. In this case, the capsule includes the cockpit, the passenger compartment and the luggage bay. When the situation demands, the capsule detaches itself automatically, in order to separate from the engines, the wings and the fin. Parachutes open during the ejection, in order to slow down the capsule.
However, these rescue capsules are particularly heavy, which makes this solution difficult to apply to passenger airliners. This type of capsule, has incidentally not been applied to any existing aircraft.
Document U.S. Pat. No. 4,699,336 also considers the use of a jettisonable survival capsule. When the situation demands, the capsule is ejected from the rear of the aircraft, after the tail of the aircraft has been ejected first. In this case, the capsule contains only the passenger cabin. As in the previous document, parachutes are used to slow the descent of the capsule so that it does not crash to the ground. For the same reason as for the capsule described in document FR-A-1 603 439, this solution is not applicable in practice to a passenger-carrying airliner.
The invention precisely concerns a device to provide access for embarking, disembarking and emergency evacuation of passengers under the conditions required by the applicable regulations, including for very large capacity aircraft, in particular of the xe2x80x9cflying wingxe2x80x9d type.
In accordance with the invention, this result is achieved using an embarkation access device, for an aircraft which includes a passenger compartment which is delimited by an aerodynamic aircraft shell, the device including at least one tunnel joined to the outside of the said aerodynamic shell, attached to a trailing edge of the latter, and extending aft in a direction approximately parallel to the aircraft longitudinal axis, and with a door normally sealing off the opening between the passenger compartment and the tunnel.
Using one or preferably, several tunnels of this type, extending the aircraft aerodynamic shell horizontally aft, it is possible to embark and disembark a large number of passengers simultaneously. In emergency situations, these same tunnels permit passengers to be evacuated to the ground in perfect safety, very rapidly.
The invention is particularly suited to aircraft of the xe2x80x9cflying wingxe2x80x9d type. In this configuration, it is possible to locate several tunnels side by side, in order to significantly reduce the time required for embarking and disembarking and in the event of emergencies, allowing for very fast evacuation of the passengers.
Thus in this case, several tunnels may advantageously by located between adjacent elevons, articulated from the trailing edge of the aerodynamic fairing of the flying wing.
In order to further enhance the flows during embarkation, disembarkation and emergency evacuation of passengers, it is advantageous to position each tunnel approximately in-line with the extended aisle formed between the seat rows in the aircraft passenger compartment.
In practice, each tunnel should ideally consist of at least one detachable part, which can be jettisoned in the event of an accident.
The rear detachable part would then preferably be articulated from the aerodynamic shell, in order to be able to hinge to one side, in the manner of a door, to permit the passengers to embark or disembark.
One particularly favourable configuration from the point of view of aerodynamic flow, is for the rear part of each tunnel to be approximately cone-shaped.
In an initial implementation mode for the invention, an inflatable evacuation slide is housed in each tunnel, inside the fixed part, on which the detachable rear part is mounted.
In an alternative implementation mode for the invention, a fixed section of each tunnel, to which the rear detachable part is attached, includes a floor which is articulated close to the threshold of the door. This floor is therefore able to hinge downwards thus forming an emergency evacuation slide for the passengers.
In this case, the articulated floor, should preferably be fitted with steps, which may for example be retractable, for embarking and disembarking passengers.
The invention also covers a flying wing fitted with an embarkation access device as defined above.